How to Know Your True Ring Size — According to Jewelry Experts

A ring size chart, easily found online or on a jeweler's website, will tell you how many millimeters the ring is, as well as the ring size the measurement correlates to. An easy way to measure your ring size is to start with a ring you already have and know fits you. Place the ring on the paper chart (like the one above) and move it along the chart until you find one that matches up with the inside circumference of your ring.